1. Technical Field
The present invention relates, generally, to data transmission over a high performance serial bus, and more particularly, to being able to append data blocks to data structures to transmit data across a serial bus network. More specifically, the invention relates to an apparatus and method capable of appending data to control data structures or data blocks prior to transmission over a serial bus network.
2. Description of the Related Art
The IEEE has proposed a new high performance serial bus standard under the P1394 standard. P1394 is a serial input/output bus whose physical media is a cable that consists of three shielded twisted pairs. P1394 allows a tree topology interconnect of nodes, systems or devices, for reducing the time typically required for turnaround among the nodes. P1394 can operate at multiple transmission rates, such as approximately 100 megabits per second, 200 megabits per second, and 400 megabits per second, and has universal interconnect capabilities for desktop systems, peripheral devices such as printers, hard disks, digital camera.
Under P1394, data transmission packets require control data structures or data blocks for identifying source and destination, length, and command information. Once the data structure is received by a destination node, the information within the data structure is used to generate a new data structure or data block for return transmission to the original source of the data structure. Once the data structure has been reformatted, a request in memory is made to locate the data sought by the initial read request within the original data structure. Unfortunately, waiting until after the data structure has been reformatted increases the amount of turnaround time needed to retrieve the data requested by the original source node.
Accordingly, what is needed is a way to dynamically link data to the data structure being reformatted so that, upon completion of the reformatting of the original data structure, the data requested is already linked for transmission, thus reducing turnaround time at the destination node before retransmission to the original source node. Also, what is needed is a way of linking the next data block for processing and transmission in order to increase the amount of data processed and transmitted.